You overslept; burnt your breakfast; spilt coffee down your shirt, and stumbled into work looking a wreck—a bit like every other Monday morning, just ten times worse. But that's OK, because you have an excuse: last night, you were watching history being made.
You were up all night waiting for Curiosity to land, then you were busy hunting down its first pictures. Hopefully you work somewhere that understands; somewhere everyone else was doing just the same.
If not, though, just tell anyone who questions your abilities today this: last night, NASA successfully started humanity's most advanced robot exploration of another planet by remotely landing a car-sized robot on the surface of Mars.
At the very least, that should have them questioning their contribution to the world—and why they didn't watch it themsevles. [XKCD]